A lever is a rigid bar which can rotate about a fixed point or a fixed line, called the axis of rotation. The point or the axis of rotation is called the fulcrum. Levers are simple machines. . . .
Pollution indicators Lichen indicate the pollution level in an area. Medium pollution is indicated by grey -green orange crusty lichens, whereas bushy, feathery lichens indicate clean air. And if air is very polluted there are no lichens at all. Lichens are the mutual association of algae and fungi. . . .
Japan Earthquake 2011 One of the deadliest earthquakes in recent times that measured 8.2 on Richter scale, shattered Japan in March 2011. This mega earthquake left behind a series of disasters and a story of destruction. Over 10,000 people lost their lives and property of worth million damaged. This resulted a major tsunami which brought destruction . . .
In this type of levers, the fulcrum is situated between the load and the effort. The effort arm may be equal or less than or more than load arm. In case the effort arm is more than load arm, a small effort is required to more load. However, if effort arm is less than load arm, a large effort is required to move load. Examples: Sea saw, Sci . . .
Types of germination There are two types of germination Epigeal germination – the cotyledon come out of the soil, become green and form first leaves of seedling. They synthesize food for a short while and then shrivel off. It is seen in bean, gourd, castor and cotton. Hypogeal germination – the cotyledons remain under the soil and . . .
Effort(E): The force applied on a machine to do some mechenical work. Load(L): The weight moved or the resistance overcome by a machine in doing some mechenical work. Fulcrum(F): A fixed point or an axil around which a machine turn i doing mechenical work. Effort arm: The perpendicular distance between the effort point and the fulcrum of a mach . . .
Essential and nonessential amino acids Plants can synthesize all the amino acids they need but animals cannot. Animals obtain amino acids either from plants or from animal proteins. Man can synthesize twelve of twenty amino acids. These amino acids are called non-essential amino acids. Amino acids which cannot be synthesized are obtained from p . . .
Newton demonstrated by his colour disc, the recombination of seven colours to produce white light. He took a circular cardboard disc and divided it into seven sectors. He painted all the seven colours(violet, indigo, blue, green, yellow, orange and red) of white light. The disc appeared white when it was rotated at a high speed. Newton thus proved that . . .
Narcotic drugs Drugs which induce sleep, feeling of wellbeing or feeling of elation or excitement are called narcotic drugs or psychotropic drugs. They influence the psychic activities. These include opium, morphine, cocaine, charas, ganja, heroin, caffeine etc. Harmful effects of taking drugs Serious damage to the nervous system. Adverse ef . . .
Biofortification Breeding of crops with higher levels of vitamins and minerals or higher proteins and healthier fats is called biofortification. This is the most practical aspect to improve the health of the people. Wheat variety with high protein content atlas66 has been used as a donor for improving cultivated wheat. The cell from microorgani . . .
Difference between agriculture is that horticulture The most notable difference from agriculture is that horticulture deals with small scale gardening and usually in enclosed gardens although this is not a necessity while agriculture is done on large scale with extensive crop cultivation. Agricu . . .
The density of sea water is greater than the density of fresh water due to dissolved salts. Thus it is easier to swim in a sea water than in freshwater. . . .
Ice floats on water because the density of ice is less than the density of water. Thus the density of a huge mass of ice, called iceberg is less than that of water , and hence, it floats on water. . . .
Whether an object floats or sinks in a liquid depends upon how dense (or heavy) the objects as compared to that liquid.When an object is immersed in a liquid , any of the following three situations can be observed: Object Sinks: If the density of an object is more than that of the liquid, the object will sink. Examples: Iron, aluminium and s . . .
The air conditioner are fixed at a certain height. This is because the cold air coming out from the air conditioner is denser and thus moves down. On the other hand, the warm air in the room is less dense and thus moves upwards. Thus, the convection currents formed, keep the room cool. . . .